MM-10702 Moving plugins to use hashicorp go-plugin. (#8978)

* Moving plugins to use hashicorp go-plugin.

* Tweaks from feedback.

1 files changed, 0 insertions, 396 deletions

diff --git a/plugin/pluginenv/environment.go b/plugin/pluginenv/environment.go
deleted file mode 100644
index f704aa5bb..000000000
--- a/plugin/pluginenv/environment.go
+++ /dev/null
@@ -1,396 +0,0 @@
-// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
-// See License.txt for license information.
-
-// Package pluginenv provides high level functionality for discovering and launching plugins.
-package pluginenv
-
-import (
-	"fmt"
-	"io/ioutil"
-	"net/http"
-	"path/filepath"
-	"sync"
-
-	"github.com/pkg/errors"
-
-	"github.com/mattermost/mattermost-server/model"
-	"github.com/mattermost/mattermost-server/plugin"
-)
-
-type APIProviderFunc func(*model.Manifest) (plugin.API, error)
-type SupervisorProviderFunc func(*model.BundleInfo) (plugin.Supervisor, error)
-
-type ActivePlugin struct {
-	BundleInfo *model.BundleInfo
-	Supervisor plugin.Supervisor
-}
-
-// Environment represents an environment that plugins are discovered and launched in.
-type Environment struct {
-	searchPath         string
-	webappPath         string
-	apiProvider        APIProviderFunc
-	supervisorProvider SupervisorProviderFunc
-	activePlugins      map[string]ActivePlugin
-	mutex              sync.RWMutex
-}
-
-type Option func(*Environment)
-
-// Creates a new environment. At a minimum, the APIProvider and SearchPath options are required.
-func New(options ...Option) (*Environment, error) {
-	env := &Environment{
-		activePlugins: make(map[string]ActivePlugin),
-	}
-	for _, opt := range options {
-		opt(env)
-	}
-	if env.supervisorProvider == nil {
-		env.supervisorProvider = DefaultSupervisorProvider
-	}
-	if env.searchPath == "" {
-		return nil, fmt.Errorf("a search path must be provided")
-	}
-	return env, nil
-}
-
-// Returns the configured webapp path.
-func (env *Environment) WebappPath() string {
-	return env.webappPath
-}
-
-// Returns the configured search path.
-func (env *Environment) SearchPath() string {
-	return env.searchPath
-}
-
-// Returns a list of all plugins found within the environment.
-func (env *Environment) Plugins() ([]*model.BundleInfo, error) {
-	return ScanSearchPath(env.searchPath)
-}
-
-// Returns a list of all currently active plugins within the environment.
-func (env *Environment) ActivePlugins() []*model.BundleInfo {
-	env.mutex.RLock()
-	defer env.mutex.RUnlock()
-
-	activePlugins := []*model.BundleInfo{}
-	for _, p := range env.activePlugins {
-		activePlugins = append(activePlugins, p.BundleInfo)
-	}
-
-	return activePlugins
-}
-
-// Returns the ids of the currently active plugins.
-func (env *Environment) ActivePluginIds() (ids []string) {
-	env.mutex.RLock()
-	defer env.mutex.RUnlock()
-
-	for id := range env.activePlugins {
-		ids = append(ids, id)
-	}
-	return
-}
-
-// Returns true if the plugin is active, false otherwise.
-func (env *Environment) IsPluginActive(pluginId string) bool {
-	env.mutex.RLock()
-	defer env.mutex.RUnlock()
-
-	for id := range env.activePlugins {
-		if id == pluginId {
-			return true
-		}
-	}
-
-	return false
-}
-
-// Activates the plugin with the given id.
-func (env *Environment) ActivatePlugin(id string, onError func(error)) error {
-	env.mutex.Lock()
-	defer env.mutex.Unlock()
-
-	if !plugin.IsValidId(id) {
-		return fmt.Errorf("invalid plugin id: %s", id)
-	}
-
-	if _, ok := env.activePlugins[id]; ok {
-		return fmt.Errorf("plugin already active: %v", id)
-	}
-	plugins, err := ScanSearchPath(env.searchPath)
-	if err != nil {
-		return err
-	}
-	var bundle *model.BundleInfo
-	for _, p := range plugins {
-		if p.Manifest != nil && p.Manifest.Id == id {
-			if bundle != nil {
-				return fmt.Errorf("multiple plugins found: %v", id)
-			}
-			bundle = p
-		}
-	}
-	if bundle == nil {
-		return fmt.Errorf("plugin not found: %v", id)
-	}
-
-	activePlugin := ActivePlugin{BundleInfo: bundle}
-
-	var supervisor plugin.Supervisor
-
-	if bundle.Manifest.Backend != nil {
-		if env.apiProvider == nil {
-			return fmt.Errorf("env missing api provider, cannot activate plugin: %v", id)
-		}
-
-		supervisor, err = env.supervisorProvider(bundle)
-		if err != nil {
-			return errors.Wrapf(err, "unable to create supervisor for plugin: %v", id)
-		}
-		api, err := env.apiProvider(bundle.Manifest)
-		if err != nil {
-			return errors.Wrapf(err, "unable to get api for plugin: %v", id)
-		}
-		if err := supervisor.Start(api); err != nil {
-			return errors.Wrapf(err, "unable to start plugin: %v", id)
-		}
-		if onError != nil {
-			go func() {
-				err := supervisor.Wait()
-				if err != nil {
-					onError(err)
-				}
-			}()
-		}
-
-		activePlugin.Supervisor = supervisor
-	}
-
-	if bundle.Manifest.Webapp != nil {
-		if env.webappPath == "" {
-			if supervisor != nil {
-				supervisor.Stop()
-			}
-			return fmt.Errorf("env missing webapp path, cannot activate plugin: %v", id)
-		}
-
-		bundlePath := filepath.Clean(bundle.Manifest.Webapp.BundlePath)
-		if bundlePath == "" || bundlePath[0] == '.' {
-			return fmt.Errorf("invalid webapp bundle path")
-		}
-		bundlePath = filepath.Join(env.searchPath, id, bundlePath)
-
-		webappBundle, err := ioutil.ReadFile(bundlePath)
-		if err != nil {
-			// Backwards compatibility for plugins where webapp.bundle_path was ignored. This should
-			// be removed eventually.
-			if webappBundle2, err2 := ioutil.ReadFile(fmt.Sprintf("%s/%s/webapp/%s_bundle.js", env.searchPath, id, id)); err2 == nil {
-				webappBundle = webappBundle2
-			} else {
-				if supervisor != nil {
-					supervisor.Stop()
-				}
-				return errors.Wrapf(err, "unable to read webapp bundle: %v", id)
-			}
-		}
-
-		err = ioutil.WriteFile(fmt.Sprintf("%s/%s_bundle.js", env.webappPath, id), webappBundle, 0644)
-		if err != nil {
-			if supervisor != nil {
-				supervisor.Stop()
-			}
-			return errors.Wrapf(err, "unable to write webapp bundle: %v", id)
-		}
-	}
-
-	env.activePlugins[id] = activePlugin
-	return nil
-}
-
-// Deactivates the plugin with the given id.
-func (env *Environment) DeactivatePlugin(id string) error {
-	env.mutex.Lock()
-	defer env.mutex.Unlock()
-
-	if activePlugin, ok := env.activePlugins[id]; !ok {
-		return fmt.Errorf("plugin not active: %v", id)
-	} else {
-		delete(env.activePlugins, id)
-		var err error
-		if activePlugin.Supervisor != nil {
-			err = activePlugin.Supervisor.Hooks().OnDeactivate()
-			if serr := activePlugin.Supervisor.Stop(); err == nil {
-				err = serr
-			}
-		}
-		return err
-	}
-}
-
-// Deactivates all plugins and gracefully shuts down the environment.
-func (env *Environment) Shutdown() (errs []error) {
-	env.mutex.Lock()
-	defer env.mutex.Unlock()
-
-	for _, activePlugin := range env.activePlugins {
-		if activePlugin.Supervisor != nil {
-			if err := activePlugin.Supervisor.Hooks().OnDeactivate(); err != nil {
-				errs = append(errs, errors.Wrapf(err, "OnDeactivate() error for %v", activePlugin.BundleInfo.Manifest.Id))
-			}
-			if err := activePlugin.Supervisor.Stop(); err != nil {
-				errs = append(errs, errors.Wrapf(err, "error stopping supervisor for %v", activePlugin.BundleInfo.Manifest.Id))
-			}
-		}
-	}
-	env.activePlugins = make(map[string]ActivePlugin)
-	return
-}
-
-type MultiPluginHooks struct {
-	env *Environment
-}
-
-type SinglePluginHooks struct {
-	env      *Environment
-	pluginId string
-}
-
-func (env *Environment) Hooks() *MultiPluginHooks {
-	return &MultiPluginHooks{
-		env: env,
-	}
-}
-
-func (env *Environment) HooksForPlugin(id string) *SinglePluginHooks {
-	return &SinglePluginHooks{
-		env:      env,
-		pluginId: id,
-	}
-}
-
-func (h *MultiPluginHooks) invoke(f func(plugin.Hooks) error) (errs []error) {
-	h.env.mutex.RLock()
-	defer h.env.mutex.RUnlock()
-
-	for _, activePlugin := range h.env.activePlugins {
-		if activePlugin.Supervisor == nil {
-			continue
-		}
-		if err := f(activePlugin.Supervisor.Hooks()); err != nil {
-			errs = append(errs, errors.Wrapf(err, "hook error for %v", activePlugin.BundleInfo.Manifest.Id))
-		}
-	}
-	return
-}
-
-// OnConfigurationChange invokes the OnConfigurationChange hook for all plugins. Any errors
-// encountered will be returned.
-func (h *MultiPluginHooks) OnConfigurationChange() []error {
-	return h.invoke(func(hooks plugin.Hooks) error {
-		if err := hooks.OnConfigurationChange(); err != nil {
-			return errors.Wrapf(err, "error calling OnConfigurationChange hook")
-		}
-		return nil
-	})
-}
-
-// ServeHTTP invokes the ServeHTTP hook for the plugin identified by the request or responds with a
-// 404 not found.
-//
-// It expects the request's context to have a plugin_id set.
-func (h *MultiPluginHooks) ServeHTTP(w http.ResponseWriter, r *http.Request) {
-	if id := r.Context().Value("plugin_id"); id != nil {
-		if idstr, ok := id.(string); ok {
-			h.env.mutex.RLock()
-			defer h.env.mutex.RUnlock()
-			if plugin, ok := h.env.activePlugins[idstr]; ok && plugin.Supervisor != nil {
-				plugin.Supervisor.Hooks().ServeHTTP(w, r)
-				return
-			}
-		}
-	}
-	http.NotFound(w, r)
-}
-
-// MessageWillBePosted invokes the MessageWillBePosted hook for all plugins. Ordering
-// is not guaranteed and the next plugin will get the previous one's modifications.
-// if a plugin rejects a post, the rest of the plugins will not know that an attempt was made.
-// Returns the final result post, or nil if the post was rejected and a string with a reason
-// for the user the message was rejected.
-func (h *MultiPluginHooks) MessageWillBePosted(post *model.Post) (*model.Post, string) {
-	h.env.mutex.RLock()
-	defer h.env.mutex.RUnlock()
-
-	for _, activePlugin := range h.env.activePlugins {
-		if activePlugin.Supervisor == nil {
-			continue
-		}
-		var rejectionReason string
-		post, rejectionReason = activePlugin.Supervisor.Hooks().MessageWillBePosted(post)
-		if post == nil {
-			return nil, rejectionReason
-		}
-	}
-	return post, ""
-}
-
-// MessageWillBeUpdated invokes the MessageWillBeUpdated hook for all plugins. Ordering
-// is not guaranteed and the next plugin will get the previous one's modifications.
-// if a plugin rejects a post, the rest of the plugins will not know that an attempt was made.
-// Returns the final result post, or nil if the post was rejected and a string with a reason
-// for the user the message was rejected.
-func (h *MultiPluginHooks) MessageWillBeUpdated(newPost, oldPost *model.Post) (*model.Post, string) {
-	h.env.mutex.RLock()
-	defer h.env.mutex.RUnlock()
-
-	post := newPost
-	for _, activePlugin := range h.env.activePlugins {
-		if activePlugin.Supervisor == nil {
-			continue
-		}
-		var rejectionReason string
-		post, rejectionReason = activePlugin.Supervisor.Hooks().MessageWillBeUpdated(post, oldPost)
-		if post == nil {
-			return nil, rejectionReason
-		}
-	}
-	return post, ""
-}
-
-func (h *MultiPluginHooks) MessageHasBeenPosted(post *model.Post) {
-	h.invoke(func(hooks plugin.Hooks) error {
-		hooks.MessageHasBeenPosted(post)
-		return nil
-	})
-}
-
-func (h *MultiPluginHooks) MessageHasBeenUpdated(newPost, oldPost *model.Post) {
-	h.invoke(func(hooks plugin.Hooks) error {
-		hooks.MessageHasBeenUpdated(newPost, oldPost)
-		return nil
-	})
-}
-
-func (h *SinglePluginHooks) invoke(f func(plugin.Hooks) error) error {
-	h.env.mutex.RLock()
-	defer h.env.mutex.RUnlock()
-
-	if activePlugin, ok := h.env.activePlugins[h.pluginId]; ok && activePlugin.Supervisor != nil {
-		if err := f(activePlugin.Supervisor.Hooks()); err != nil {
-			return errors.Wrapf(err, "hook error for plugin: %v", activePlugin.BundleInfo.Manifest.Id)
-		}
-		return nil
-	}
-	return fmt.Errorf("unable to invoke hook for plugin: %v", h.pluginId)
-}
-
-// ExecuteCommand invokes the ExecuteCommand hook for the plugin.
-func (h *SinglePluginHooks) ExecuteCommand(args *model.CommandArgs) (resp *model.CommandResponse, appErr *model.AppError, err error) {
-	err = h.invoke(func(hooks plugin.Hooks) error {
-		resp, appErr = hooks.ExecuteCommand(args)
-		return nil
-	})
-	return
-}